During yesterday's confirmation hearing for Scott Pruitt - who is nominated to head the Environmental Protection Agency - he was questioned by Kamala Harris.

California's newly-elected junior senator pushed Pruitt on whether he'd continue to allow California to set its own vehicle emissions standards.

That's something the state has done since the 1970s. Here's a bit of that exchange:

HARRIS: Do you agree to uphold that same standard that has been held by your previous administrators…

PRUITT: I agree to review it it as each administrator before me has. It has been granted at times…

HARRIS: Do you agree to uphold it? Reviewing it and upholding it are two different points.

PRUITT: Senator as you know, administrators in the past have not granted the waiver, and in fact have granted the waiver. That's a review process that will be conducted…

HARRIS: What is your intention sir?

PRUITT: I don't know without going through the process to determine that Senator. And one would not want to presume the outcome.

What is the history of California's emissions policies? How does Pruitt's past challenging EPA's so-called overreach align with his answers on the Hill yesterday? AirTalk speaks with LA Times politics reporter Evan Halper, along with EarthJustice attorney Adrian Martinez and Heritage energy policy expert Nick Loris.

This segment is being updated.

Guests:

Adrian Martinez, staff attorney at the environmental law firm, EarthJustice

Nicolas (Nick) Loris, an economist who focuses on energy, environmental, and regulatory issues as the Herbert and Joyce Morgan fellow at The Heritage Foundation - a conservative think tank based in Washington, D.C.